Additional Information

12 Months Ended

Dec. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Additional Information

Additional Information

	For the Years Ended December 31,
(in millions)	2021		2020		2019
Research and development expense	$	145	$	131	$	168
Interest and other debt expense, net:
Interest expense	$	1,188	$	1,223	$	1,322
Interest income	(26)		(14)		(42)
	$	1,162	$	1,209	$	1,280

The activity in the allowance for discounts and allowance for returned goods was as follows:

	For the Years Ended December 31,
(in millions)	2021				2020				2019
	Discounts		Returned Goods		Discounts		Returned Goods		Discounts		Returned Goods
Balance at beginning of year	$	—	$	40	$	—	$	32	$	—	$	32
Charged to costs and expenses	647		124		633		98		604		127
Deductions (1)	(647)		(114)		(633)		(90)		(604)		(127)
Balance at end of year	$	—	$	50	$	—	$	40	$	—	$	32

(1) Represents the recording of discounts and returns for which allowances were created.